Package reorg part 3

- binary "inbucketd" is now "inbucket"
 - renamed "conf" to "etc" so it doesn't get confused with "config" pacakge dir

inbucket.go

@@ -41,7 +41,7 @@ func main() {
 
 func init() {
 	flag.Usage = func() {
-		fmt.Fprintln(os.Stderr, "Usage of inbucketd [options] <conf file>:")
+		fmt.Fprintln(os.Stderr, "Usage of inbucket [options] <conf file>:")
 		flag.PrintDefaults()
 	}
 }